This invention relates to combustible compositions, consisting of or comprising: mixtures of one or more easily oxidizable, powdered metals and one or more powdered oxidizing agents, which mixtures are able to generate aerosols to be employed, in particular, to control and/or to modify weather, such as to clear fogs, to modify clouds, to prevent hail.
This invention relates also to the process for the aerosolization of the reaction products of said compositions realized by oxidizing said metal/s with said oxidizing agents. More precisely, the compositions of the present invention are able to give, after "giant condensation nuclei" and/or "giant freezing nuclei" for the purposes stated above.
This invention further relates to an aerosolization process of various substances which are contained in mixtures comprising one or more easily oxidizable, powdered metals and powdered oxidizing agents, the aerosolization being the consequence of the combustion of the above defined mixtures and/or of the melting or vaporization of suitable salts embodied in the mixtures.
It is known that various inorganic and organic substances have been employed as smokes or dispersions for ice nucleation in super-cooled clouds; among these known substances mention is made of silver and lead iodides as well as the carbon dioxide.
the use of suspended or dissolved, powdered or vaporized hygroscopic substances is also known to induce coalescence of the water drops into clouds or in fog; we cite among these known substances, as potential agents, the activated sodium or potassium chlorides, that is, the sodium or potassium chlorides which show defective crystalline lattice, caused by ionizing radiations.
Various methods and devices have been used up to date to generate aerosols from the known substances; for example, burners fed with solutions of silver iodide in acetone have been used, or also containers containing said substances finely subdivided which is then dispersed by means of an explosive charge of gunpowder. The use of aircrafts, helicopters, aerostats and also rockets provided with a head charged with the product to be aerosolized and with a bursting charge suitable to realize the dispersion is also known for the purpose of transporting the substances to be aerosolized and the aerosolization devices in the atmosphere zones wherein a weather modification is desired.
Particularly the substances used up to this time, but also the known methods and devices for dispersing them to control and/or modify weather, show a number of disadvantages.
The silver iodide, which up to now has been considered the best artificial ice-nucleant and is the most commonly used for this purpose, besides being considerably expensive promptly decays in its nucleating activity under the action of both light or moisture. Further its high cost confines its employment in practice to dispersions having very small particles i.e. particles whose sizes are comparable with those of the colloidal water which constitutes the clouds; as a consequence said particles are not able to mechanically sweep away the colloidal water of the clouds.
Many other solid, hygroscopic substances, capable of coalescing water vapour in clouds, etc. have the disadvantages that the ground product, which must be finely subdivided (about 30 microns or less) and dry to avoid reagglomeration and caking phenomena shown by said hygroscopic particles in the presence of low moisture content. In particular, cumbersome apparatuses are needed to obtain sodium or potassium chlorides or generally speaking, alkali-metal halides provided with a defective crystalline lattice.
Also the methods now in use to produce aerosols present various disadvantages, since they require dispersing or burning devices or other bulky and/or heavy apparatuses which in turn require special equipment for their transport and functioning.